{"id":33000,"date":"2025-09-08T10:02:12","date_gmt":"2025-09-08T03:02:12","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=33000"},"modified":"2025-11-18T11:37:42","modified_gmt":"2025-11-18T04:37:42","slug":"data-link-layer-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/","title":{"rendered":"Data Link Layer l\u00e0 g\u00ec? Ch\u1ee9c n\u0103ng, V\u1ecb tr\u00ed &#038; V\u00ed d\u1ee5 t\u1ea7ng Data Link"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-white ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">N\u1ed8I DUNG<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Data-Link-Layer-la-gi\" >Data Link Layer l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Vi-tri-cua-Data-Link-Layer-trong-mo-hinh-OSI\" >V\u1ecb tr\u00ed c\u1ee7a Data Link Layer trong m\u00f4 h\u00ecnh OSI<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#2-lop-con-quan-trong-cua-Data-Link-Layer\" >2 l\u1edbp con quan tr\u1ecdng c\u1ee7a Data Link Layer<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Lop-con-Dieu-khien-lien-ket-logic-LLC-%E2%80%93-Logical-Link-Control\" >L\u1edbp con \u0110i\u1ec1u khi\u1ec3n li\u00ean k\u1ebft logic (LLC &#8211; Logical Link Control)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Lop-con-Dieu-khien-truy-cap-phuong-tien-MAC-%E2%80%93-Media-Access-Control\" >L\u1edbp con \u0110i\u1ec1u khi\u1ec3n truy c\u1eadp ph\u01b0\u01a1ng ti\u1ec7n (MAC &#8211; Media Access Control)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Cac-chuc-nang-chinh-cua-Data-Link-Layer\" >C\u00e1c ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Data Link Layer<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Phan-khung-Framing\" >Ph\u00e2n khung (Framing)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Kiem-soat-luong-Flow-Control\" >Ki\u1ec3m so\u00e1t lu\u1ed3ng (Flow Control)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Kiem-soat-loi-Error-Control\" >Ki\u1ec3m so\u00e1t l\u1ed7i (Error Control)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Dieu-khien-truy-cap-moi-truong-MAC\" >\u0110i\u1ec1u khi\u1ec3n truy c\u1eadp m\u00f4i tr\u01b0\u1eddng (MAC)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Cac-giao-thuc-pho-bien-o-Tang-Data-Link-Layer\" >C\u00e1c giao th\u1ee9c ph\u1ed5 bi\u1ebfn \u1edf T\u1ea7ng Data Link Layer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Thiet-bi-hoat-dong-o-Tang-Data-Link-Layer\" >Thi\u1ebft b\u1ecb ho\u1ea1t \u0111\u1ed9ng \u1edf T\u1ea7ng Data Link Layer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#So-sanh-Data-Link-Layer-va-Network-Layer\" >So s\u00e1nh Data Link Layer v\u00e0 Network Layer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Vi-du-thuc-te-ve-Data-Link-Layer\" >V\u00ed d\u1ee5 th\u1ef1c t\u1ebf v\u1ec1 Data Link Layer<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/#Vai-tro-cua-Data-Link-Layer-trong-truyen-thong-mang\" >Vai tr\u00f2 c\u1ee7a Data Link Layer trong truy\u1ec1n th\u00f4ng m\u1ea1ng<\/a><\/li><\/ul><\/nav><\/div>\n<p>Trong m\u1ea1ng m\u00e1y t\u00ednh, m\u00f4 h\u00ecnh OSI (Open Systems Interconnection) l\u00e0 n\u1ec1n t\u1ea3ng quan tr\u1ecdng gi\u00fap ta hi\u1ec3u r\u00f5 c\u00e1ch d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n t\u1eeb thi\u1ebft b\u1ecb n\u00e0y sang thi\u1ebft b\u1ecb kh\u00e1c. Trong s\u1ed1 7 t\u1ea7ng c\u1ee7a m\u00f4 h\u00ecnh OSI, Data Link Layer (T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u) gi\u1eef vai tr\u00f2 \u0111\u1eb7c bi\u1ec7t. V\u1eady <a href=\"https:\/\/interdata.vn\/blog\/data-link-layer-la-gi\/\"><strong>Data Link Layer l\u00e0 g\u00ec<\/strong><\/a>, c\u00f3 nh\u1eefng t\u00ednh n\u0103ng g\u00ec, v\u00e0 ho\u1ea1t \u0111\u1ed9ng c\u1ee7a t\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u kh\u00e1c g\u00ec so c\u00e1c t\u1ea7ng <a href=\"https:\/\/interdata.vn\/blog\/physical-layer-la-gi\/\">Physical Layer<\/a> hay Network Layer? T\u00ecm hi\u1ec3u ngay!<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Data-Link-Layer-la-gi\"><\/span>Data Link Layer l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Data Link Layer l\u00e0 t\u1ea7ng th\u1ee9 hai trong m\u00f4 h\u00ecnh OSI 7 l\u1edbp<\/strong>, n\u1eb1m ngay tr\u00ean T\u1ea7ng v\u1eadt l\u00fd (Physical Layer) v\u00e0 d\u01b0\u1edbi T\u1ea7ng m\u1ea1ng (Network Layer). T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u ch\u1ecbu tr\u00e1ch nhi\u1ec7m ch\u00ednh trong vi\u1ec7c truy\u1ec1n t\u1ea3i c\u00e1c &#8220;khung&#8221; (frame) d\u1eef li\u1ec7u t\u1eeb m\u1ed9t n\u00fat (node) m\u1ea1ng n\u00e0y \u0111\u1ebfn m\u1ed9t n\u00fat m\u1ea1ng kh\u00e1c.<\/p>\n<p>T\u1ea7ng Data Link Layer gi\u00fap ph\u00e1t hi\u1ec7n v\u00e0 s\u1eeda l\u1ed7i trong qu\u00e1 tr\u00ecnh truy\u1ec1n, \u0111\u1ed3ng th\u1eddi qu\u1ea3n l\u00fd lu\u1ed3ng d\u1eef li\u1ec7u \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o m\u00e1y nh\u1eadn kh\u00f4ng b\u1ecb qu\u00e1 t\u1ea3i.<\/p>\n<figure id=\"attachment_33005\" aria-describedby=\"caption-attachment-33005\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33005\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Data-Link-Layer-la-gi.jpg\" alt=\"Data Link Layer l\u00e0 g\u00ec\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Data-Link-Layer-la-gi.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Data-Link-Layer-la-gi-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Data-Link-Layer-la-gi-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33005\" class=\"wp-caption-text\">Data Link Layer l\u00e0 g\u00ec?<\/figcaption><\/figure>\n<p>H\u00e3y h\u00ecnh dung th\u1ebf n\u00e0y: n\u1ebfu T\u1ea7ng m\u1ea1ng (Network Layer) gi\u1ed1ng nh\u01b0 vi\u1ec7c b\u1ea1n g\u1eedi m\u1ed9t b\u1ee9c th\u01b0 c\u00f3 \u0111\u1ecba ch\u1ec9 nh\u00e0 (<a href=\"https:\/\/interdata.vn\/blog\/dia-chi-ip-la-gi\/\">\u0111\u1ecba ch\u1ec9 IP<\/a>) \u0111\u1ec3 chuy\u1ec3n \u0111\u1ebfn m\u1ed9t th\u00e0nh ph\u1ed1 c\u1ee5 th\u1ec3, th\u00ec Data Link Layer ch\u00ednh l\u00e0 quy tr\u00ecnh \u0111\u1ea3m b\u1ea3o b\u1ee9c th\u01b0 \u0111\u00f3 \u0111\u01b0\u1ee3c giao ch\u00ednh x\u00e1c t\u1eeb b\u01b0u \u0111i\u1ec7n n\u00e0y \u0111\u1ebfn b\u01b0u \u0111i\u1ec7n kh\u00e1c tr\u00ean c\u00f9ng m\u1ed9t tuy\u1ebfn \u0111\u01b0\u1eddng (\u0111\u1ecba ch\u1ec9 MAC).<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Vi-tri-cua-Data-Link-Layer-trong-mo-hinh-OSI\"><\/span>V\u1ecb tr\u00ed c\u1ee7a Data Link Layer trong m\u00f4 h\u00ecnh OSI<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u, hay Data Link Layer, c\u00f3 m\u1ed9t v\u1ecb tr\u00ed chi\u1ebfn l\u01b0\u1ee3c trong m\u00f4 h\u00ecnh OSI. N\u00f3 \u0111\u00f3ng vai tr\u00f2 trung gian, k\u1ebft n\u1ed1i T\u1ea7ng v\u1eadt l\u00fd (Physical Layer) \u2013 n\u01a1i x\u1eed l\u00fd t\u00edn hi\u1ec7u \u0111i\u1ec7n, c\u00e1p m\u1ea1ng \u2013 v\u1edbi T\u1ea7ng m\u1ea1ng (Network Layer) \u2013 n\u01a1i x\u1eed l\u00fd \u0111\u1ecba ch\u1ec9 logic v\u00e0 \u0111\u1ecbnh tuy\u1ebfn.<\/p>\n<p>B\u1ea1n c\u00f3 th\u1ec3 d\u1ec5 d\u00e0ng h\u00ecnh dung v\u1ecb tr\u00ed c\u1ee7a n\u00f3 qua s\u01a1 \u0111\u1ed3 d\u01b0\u1edbi \u0111\u00e2y:<\/p>\n<figure id=\"attachment_33001\" aria-describedby=\"caption-attachment-33001\" style=\"width: 602px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33001\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Vi-tri-cua-Data-Link-Layer-trong-mo-hinh-OSI.png\" alt=\"V\u1ecb tr\u00ed c\u1ee7a Data Link Layer trong m\u00f4 h\u00ecnh OSI\" width=\"602\" height=\"876\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Vi-tri-cua-Data-Link-Layer-trong-mo-hinh-OSI.png 602w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Vi-tri-cua-Data-Link-Layer-trong-mo-hinh-OSI-206x300.png 206w\" sizes=\"auto, (max-width: 602px) 100vw, 602px\" \/><figcaption id=\"caption-attachment-33001\" class=\"wp-caption-text\">V\u1ecb tr\u00ed c\u1ee7a Data Link Layer trong m\u00f4 h\u00ecnh OSI<\/figcaption><\/figure>\n<p>V\u1ecb tr\u00ed n\u00e0y gi\u00fap Data Link Layer d\u1ec5 d\u00e0ng nh\u1eadn d\u1eef li\u1ec7u th\u00f4 t\u1eeb T\u1ea7ng v\u1eadt l\u00fd, x\u1eed l\u00fd ch\u00fang th\u00e0nh c\u00e1c khung d\u1eef li\u1ec7u c\u00f3 c\u1ea5u tr\u00fac, sau \u0111\u00f3 chuy\u1ec3n l\u00ean T\u1ea7ng m\u1ea1ng \u0111\u1ec3 x\u1eed l\u00fd logic cao h\u01a1n. \u0110\u1ed3ng th\u1eddi, t\u1ea7ng n\u00e0y c\u0169ng nh\u1eadn g\u00f3i d\u1eef li\u1ec7u t\u1eeb T\u1ea7ng m\u1ea1ng, \u0111\u00f3ng g\u00f3i ch\u00fang th\u00e0nh c\u00e1c khung v\u00e0 truy\u1ec1n \u0111i qua T\u1ea7ng v\u1eadt l\u00fd.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"2-lop-con-quan-trong-cua-Data-Link-Layer\"><\/span><strong>2 l\u1edbp con quan tr\u1ecdng c\u1ee7a Data Link Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 th\u1ef1c hi\u1ec7n c\u00e1c ch\u1ee9c n\u0103ng ph\u1ee9c t\u1ea1p, T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u\u00a0\u0111\u01b0\u1ee3c chia th\u00e0nh hai l\u1edbp con:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Lop-con-Dieu-khien-lien-ket-logic-LLC-%E2%80%93-Logical-Link-Control\"><\/span><strong>L\u1edbp con \u0110i\u1ec1u khi\u1ec3n li\u00ean k\u1ebft logic (LLC &#8211; Logical Link Control)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>L\u1edbp Logical Link Control c\u00f3 ch\u1ee9c n\u0103ng qu\u1ea3n l\u00fd vi\u1ec7c truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa c\u00e1c thi\u1ebft b\u1ecb tr\u00ean c\u00f9ng m\u1ed9t m\u1ea1ng. LLC ch\u1ecbu tr\u00e1ch nhi\u1ec7m ph\u00e1t hi\u1ec7n l\u1ed7i, \u0111i\u1ec1u khi\u1ec3n lu\u1ed3ng d\u1eef li\u1ec7u v\u00e0 cung c\u1ea5p c\u00e1c \u0111i\u1ec3m d\u1ecbch v\u1ee5 cho T\u1ea7ng m\u1ea1ng. L\u1edbp LLC cho ph\u00e9p c\u00e1c giao th\u1ee9c T\u1ea7ng m\u1ea1ng kh\u00e1c nhau (nh\u01b0 IP, IPX) s\u1eed d\u1ee5ng chung m\u1ed9t giao th\u1ee9c T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Lop-con-Dieu-khien-truy-cap-phuong-tien-MAC-%E2%80%93-Media-Access-Control\"><\/span><strong>L\u1edbp con \u0110i\u1ec1u khi\u1ec3n truy c\u1eadp ph\u01b0\u01a1ng ti\u1ec7n (MAC &#8211; Media Access Control)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Media Access Control l\u00e0 l\u1edbp con ch\u1ecbu tr\u00e1ch nhi\u1ec7m x\u00e1c \u0111\u1ecbnh \u0111\u1ecba ch\u1ec9 v\u1eadt l\u00fd c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb trong m\u1ea1ng, th\u01b0\u1eddng \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u0111\u1ecba ch\u1ec9 MAC. <strong>Data Link Layer<\/strong> s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 MAC \u0111\u1ec3 truy\u1ec1n khung d\u1eef li\u1ec7u t\u1eeb m\u1ed9t thi\u1ebft b\u1ecb c\u1ee5 th\u1ec3 \u0111\u1ebfn m\u1ed9t thi\u1ebft b\u1ecb kh\u00e1c trong c\u00f9ng m\u1ed9t ph\u00e2n \u0111o\u1ea1n m\u1ea1ng. L\u1edbp n\u00e0y c\u0169ng qu\u1ea3n l\u00fd vi\u1ec7c truy c\u1eadp v\u00e0o m\u00f4i tr\u01b0\u1eddng truy\u1ec1n t\u1ea3i chung, ng\u0103n ng\u1eeba xung \u0111\u1ed9t d\u1eef li\u1ec7u.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-chuc-nang-chinh-cua-Data-Link-Layer\"><\/span><strong>C\u00e1c ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Data Link Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Data Link Layer<\/strong> th\u1ef1c hi\u1ec7n nhi\u1ec1u ch\u1ee9c n\u0103ng quan tr\u1ecdng \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o vi\u1ec7c truy\u1ec1n d\u1eef li\u1ec7u di\u1ec5n ra hi\u1ec7u qu\u1ea3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Phan-khung-Framing\"><\/span><strong>Ph\u00e2n khung (Framing)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ch\u1ee9c n\u0103ng \u0111\u1ea7u ti\u00ean v\u00e0 c\u01a1 b\u1ea3n nh\u1ea5t l\u00e0 ph\u00e2n khung. <strong>Data Link Layer<\/strong> nh\u1eadn c\u00e1c g\u00f3i d\u1eef li\u1ec7u t\u1eeb T\u1ea7ng m\u1ea1ng v\u00e0 \u0111\u00f3ng g\u00f3i ch\u00fang th\u00e0nh c\u00e1c khung (frame). M\u1ed7i khung d\u1eef li\u1ec7u c\u00f3 m\u1ed9t c\u1ea5u tr\u00fac ri\u00eang, bao g\u1ed3m: ti\u00eau \u0111\u1ec1 (<a href=\"https:\/\/interdata.vn\/blog\/header-la-gi\/\">header<\/a>), d\u1eef li\u1ec7u (payload) v\u00e0 ph\u1ea7n k\u1ebft th\u00fac (trailer). Ti\u00eau \u0111\u1ec1 khung ch\u1ee9a \u0111\u1ecba ch\u1ec9 MAC c\u1ee7a ngu\u1ed3n v\u00e0 \u0111\u00edch, gi\u00fap x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1eddng \u0111i c\u1ee7a d\u1eef li\u1ec7u trong m\u1ea1ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kiem-soat-luong-Flow-Control\"><\/span><strong>Ki\u1ec3m so\u00e1t lu\u1ed3ng (Flow Control)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ki\u1ec3m so\u00e1t lu\u1ed3ng gi\u00fap \u0111i\u1ec1u ch\u1ec9nh t\u1ed1c \u0111\u1ed9 truy\u1ec1n d\u1eef li\u1ec7u gi\u1eefa m\u00e1y g\u1eedi v\u00e0 m\u00e1y nh\u1eadn. N\u1ebfu m\u00e1y g\u1eedi truy\u1ec1n d\u1eef li\u1ec7u qu\u00e1 nhanh trong khi m\u00e1y nh\u1eadn kh\u00f4ng th\u1ec3 x\u1eed l\u00fd k\u1ecbp, d\u1eef li\u1ec7u s\u1ebd b\u1ecb m\u1ea5t. Ch\u1ee9c n\u0103ng n\u00e0y c\u1ee7a <strong>Data Link Layer<\/strong> \u0111\u1ea3m b\u1ea3o m\u00e1y nh\u1eadn c\u00f3 th\u1ec3 x\u1eed l\u00fd t\u1ea5t c\u1ea3 c\u00e1c khung d\u1eef li\u1ec7u m\u1ed9t c\u00e1ch hi\u1ec7u qu\u1ea3, tr\u00e1nh t\u00ecnh tr\u1ea1ng qu\u00e1 t\u1ea3i.<\/p>\n<figure id=\"attachment_33006\" aria-describedby=\"caption-attachment-33006\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33006\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cac-chuc-nang-chinh-cua-Data-Link-Layer.jpg\" alt=\"C\u00e1c ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Data Link Layer\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cac-chuc-nang-chinh-cua-Data-Link-Layer.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cac-chuc-nang-chinh-cua-Data-Link-Layer-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/Cac-chuc-nang-chinh-cua-Data-Link-Layer-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33006\" class=\"wp-caption-text\">C\u00e1c ch\u1ee9c n\u0103ng ch\u00ednh c\u1ee7a Data Link Layer<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Kiem-soat-loi-Error-Control\"><\/span><strong>Ki\u1ec3m so\u00e1t l\u1ed7i (Error Control)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u ch\u1ecbu tr\u00e1ch nhi\u1ec7m ph\u00e1t hi\u1ec7n v\u00e0 s\u1eeda l\u1ed7i trong qu\u00e1 tr\u00ecnh truy\u1ec1n. Khi d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n qua T\u1ea7ng v\u1eadt l\u00fd, nhi\u1ec5u \u0111i\u1ec7n t\u1eeb ho\u1eb7c c\u00e1c s\u1ef1 c\u1ed1 kh\u00e1c c\u00f3 th\u1ec3 l\u00e0m h\u1ecfng bit d\u1eef li\u1ec7u. Ch\u1ee9c n\u0103ng n\u00e0y s\u1eed d\u1ee5ng c\u00e1c k\u1ef9 thu\u1eadt nh\u01b0 ki\u1ec3m tra ch\u1eb5n l\u1ebb (parity check) ho\u1eb7c CRC (Cyclic Redundancy Check) \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o d\u1eef li\u1ec7u nh\u1eadn \u0111\u01b0\u1ee3c gi\u1ed1ng h\u1ec7t d\u1eef li\u1ec7u \u0111\u00e3 g\u1eedi.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Dieu-khien-truy-cap-moi-truong-MAC\"><\/span><strong>\u0110i\u1ec1u khi\u1ec3n truy c\u1eadp m\u00f4i tr\u01b0\u1eddng (MAC)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ch\u1ee9c n\u0103ng n\u00e0y qu\u1ea3n l\u00fd quy\u1ec1n truy c\u1eadp c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb v\u00e0o m\u00f4i tr\u01b0\u1eddng truy\u1ec1n t\u1ea3i chung. Trong m\u1ed9t <a href=\"https:\/\/interdata.vn\/blog\/mang-lan\/\">m\u1ea1ng LAN<\/a>, nhi\u1ec1u thi\u1ebft b\u1ecb c\u00f3 th\u1ec3 mu\u1ed1n g\u1eedi d\u1eef li\u1ec7u c\u00f9ng m\u1ed9t l\u00fac. L\u1edbp MAC s\u1ebd c\u00f3 c\u00e1c quy t\u1eafc \u0111\u1ec3 x\u1eed l\u00fd t\u00ecnh hu\u1ed1ng n\u00e0y, v\u00ed d\u1ee5 nh\u01b0 giao th\u1ee9c CSMA\/CD trong m\u1ea1ng Ethernet, gi\u00fap tr\u00e1nh xung \u0111\u1ed9t d\u1eef li\u1ec7u.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cac-giao-thuc-pho-bien-o-Tang-Data-Link-Layer\"><\/span><strong>C\u00e1c giao th\u1ee9c ph\u1ed5 bi\u1ebfn \u1edf T\u1ea7ng Data Link Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>C\u00f3 nhi\u1ec1u giao th\u1ee9c ho\u1ea1t \u0111\u1ed9ng t\u1ea1i T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u, m\u1ed7i giao th\u1ee9c ph\u00f9 h\u1ee3p v\u1edbi m\u1ed9t lo\u1ea1i m\u1ea1ng c\u1ee5 th\u1ec3.<\/p>\n<ul>\n<li><strong>Ethernet:<\/strong> \u0110\u00e2y l\u00e0 giao th\u1ee9c T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u ph\u1ed5 bi\u1ebfn nh\u1ea5t trong c\u00e1c m\u1ea1ng LAN c\u00f3 d\u00e2y. Ethernet s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 MAC \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c thi\u1ebft b\u1ecb v\u00e0 truy\u1ec1n c\u00e1c khung d\u1eef li\u1ec7u. Ng\u00e0y nay, c\u00e1c phi\u00ean b\u1ea3n Ethernet c\u00f3 th\u1ec3 \u0111\u1ea1t t\u1ed1c \u0111\u1ed9 10 Gbps ho\u1eb7c cao h\u01a1n.<\/li>\n<li><strong>Wi-Fi (802.11):<\/strong> Giao th\u1ee9c n\u00e0y cho ph\u00e9p c\u00e1c thi\u1ebft b\u1ecb k\u1ebft n\u1ed1i kh\u00f4ng d\u00e2y. T\u01b0\u01a1ng t\u1ef1 Ethernet, Wi-Fi c\u0169ng s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 MAC \u0111\u1ec3 qu\u1ea3n l\u00fd c\u00e1c thi\u1ebft b\u1ecb trong m\u1ea1ng WLAN.<\/li>\n<li><strong>PPP (Point-to-Point Protocol):<\/strong> PPP th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 thi\u1ebft l\u1eadp k\u1ebft n\u1ed1i gi\u1eefa hai \u0111i\u1ec3m bao g\u1ed3m dial-up truy\u1ec1n th\u1ed1ng, leased line v\u00e0 m\u1ed9t s\u1ed1 tunnel.<\/li>\n<li><strong>HDLC (High-Level Data Link Control):<\/strong> HDLC l\u00e0 m\u1ed9t giao th\u1ee9c bit-oriented, th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong c\u00e1c m\u1ea1ng di\u1ec7n r\u1ed9ng (WAN).<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Thiet-bi-hoat-dong-o-Tang-Data-Link-Layer\"><\/span><strong>Thi\u1ebft b\u1ecb ho\u1ea1t \u0111\u1ed9ng \u1edf T\u1ea7ng Data Link Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>M\u1ed9t s\u1ed1 thi\u1ebft b\u1ecb m\u1ea1ng \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1eb7c bi\u1ec7t \u0111\u1ec3 ho\u1ea1t \u0111\u1ed9ng t\u1ea1i <strong>Data Link Layer<\/strong>.<\/p>\n<ul>\n<li><strong>Switch (B\u1ed9 chuy\u1ec3n m\u1ea1ch):<\/strong> \u0110\u00e2y l\u00e0 thi\u1ebft b\u1ecb m\u1ea1ng quan tr\u1ecdng nh\u1ea5t ho\u1ea1t \u0111\u1ed9ng \u1edf T\u1ea7ng 2. Switch s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 MAC \u0111\u1ec3 chuy\u1ec3n ti\u1ebfp c\u00e1c khung d\u1eef li\u1ec7u t\u1eeb m\u1ed9t c\u1ed5ng n\u00e0y sang m\u1ed9t c\u1ed5ng kh\u00e1c. Switch duy tr\u00ec m\u1ed9t b\u1ea3ng \u0111\u1ecba ch\u1ec9 MAC, gi\u00fap n\u00f3 h\u1ecdc v\u00e0 ghi nh\u1edb v\u1ecb tr\u00ed c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb trong m\u1ea1ng \u0111\u1ec3 g\u1eedi d\u1eef li\u1ec7u hi\u1ec7u qu\u1ea3.<\/li>\n<li><strong>Bridge (C\u1ea7u n\u1ed1i):<\/strong> Bridge c\u00f3 ch\u1ee9c n\u0103ng t\u01b0\u01a1ng t\u1ef1 nh\u01b0 switch, nh\u01b0ng th\u01b0\u1eddng ch\u1ec9 c\u00f3 hai ho\u1eb7c ba c\u1ed5ng. Bridge \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 k\u1ebft n\u1ed1i hai ph\u00e2n \u0111o\u1ea1n m\u1ea1ng kh\u00e1c nhau, gi\u00fap gi\u1ea3m b\u1edbt l\u01b0u l\u01b0\u1ee3ng truy c\u1eadp.<\/li>\n<li><strong>Card m\u1ea1ng (NIC &#8211; Network Interface Card):<\/strong> M\u1ed7i card m\u1ea1ng tr\u00ean m\u00e1y t\u00ednh c\u1ee7a b\u1ea1n \u0111\u1ec1u c\u00f3 m\u1ed9t \u0111\u1ecba ch\u1ec9 MAC duy nh\u1ea5t. Card m\u1ea1ng ho\u1ea1t \u0111\u1ed9ng \u1edf <strong>Data Link Layer<\/strong> v\u00e0 T\u1ea7ng v\u1eadt l\u00fd \u0111\u1ec3 x\u1eed l\u00fd c\u00e1c khung d\u1eef li\u1ec7u.<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"So-sanh-Data-Link-Layer-va-Network-Layer\"><\/span>So s\u00e1nh Data Link Layer v\u00e0 Network Layer<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Nhi\u1ec1u ng\u01b0\u1eddi th\u01b0\u1eddng nh\u1ea7m l\u1eabn gi\u1eefa T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u (T\u1ea7ng 2) v\u00e0 T\u1ea7ng m\u1ea1ng (T\u1ea7ng 3) v\u00ec c\u1ea3 hai \u0111\u1ec1u li\u00ean quan \u0111\u1ebfn \u0111\u1ecba ch\u1ec9. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng kh\u00e1c bi\u1ec7t c\u01a1 b\u1ea3n:<\/p>\n<ul>\n<li><strong>Lo\u1ea1i \u0111\u1ecba ch\u1ec9<\/strong>: Data Link Layer s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 v\u1eadt l\u00fd, c\u1ee5 th\u1ec3 l\u00e0 \u0111\u1ecba ch\u1ec9 MAC. \u0110\u1ecba ch\u1ec9 MAC l\u00e0 duy nh\u1ea5t cho m\u1ed7i card m\u1ea1ng tr\u00ean to\u00e0n th\u1ebf gi\u1edbi. Ng\u01b0\u1ee3c l\u1ea1i, T\u1ea7ng m\u1ea1ng s\u1eed d\u1ee5ng \u0111\u1ecba ch\u1ec9 logic, v\u00ed d\u1ee5 nh\u01b0 \u0111\u1ecba ch\u1ec9 IP, \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00e1c thi\u1ebft b\u1ecb tr\u00ean c\u00e1c m\u1ea1ng kh\u00e1c nhau.<\/li>\n<li><strong>Ph\u1ea1m vi ho\u1ea1t \u0111\u1ed9ng<\/strong>: T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u ch\u1ec9 l\u00e0m vi\u1ec7c trong m\u1ed9t m\u1ea1ng c\u1ee5c b\u1ed9 (LAN), c\u00f2n T\u1ea7ng m\u1ea1ng l\u00e0m vi\u1ec7c tr\u00ean to\u00e0n c\u1ea7u, gi\u00fap c\u00e1c thi\u1ebft b\u1ecb li\u00ean l\u1ea1c qua <a href=\"https:\/\/interdata.vn\/blog\/mang-internet\/\">Internet<\/a>.<\/li>\n<li><strong>\u0110\u01a1n v\u1ecb d\u1eef li\u1ec7u<\/strong>: \u0110\u01a1n v\u1ecb d\u1eef li\u1ec7u \u1edf Data Link Layer l\u00e0 khung (frame), trong khi \u0111\u01a1n v\u1ecb \u1edf T\u1ea7ng m\u1ea1ng l\u00e0 g\u00f3i (packet).<\/li>\n<\/ul>\n<figure id=\"attachment_33007\" aria-describedby=\"caption-attachment-33007\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-33007\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/So-sanh-Data-Link-Layer-va-Network-Layer.jpg\" alt=\"So s\u00e1nh Data Link Layer v\u00e0 Network Layer\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/So-sanh-Data-Link-Layer-va-Network-Layer.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/So-sanh-Data-Link-Layer-va-Network-Layer-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/09\/So-sanh-Data-Link-Layer-va-Network-Layer-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-33007\" class=\"wp-caption-text\">So s\u00e1nh Data Link Layer v\u00e0 Network Layer<\/figcaption><\/figure>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 b\u1ea3ng so s\u00e1nh chi ti\u1ebft gi\u1eefa Data Link Layer v\u00e0 Network Layer:<\/p>\n<table style=\"width: 100%; border-collapse: collapse; font-family: Arial, Helvetica, sans-serif; font-size: 14px; border: 1px solid #0D6EFD;\">\n<thead>\n<tr>\n<th style=\"background: #0d6efd; color: #ffffff; padding: 12px; border: 1px solid #0d6efd; text-align: center;\">Ti\u00eau ch\u00ed so s\u00e1nh<\/th>\n<th style=\"background: #0d6efd; color: #ffffff; padding: 12px; border: 1px solid #0d6efd; text-align: center;\">Data Link Layer (T\u1ea7ng 2)<\/th>\n<th style=\"background: #0d6efd; color: #ffffff; padding: 12px; border: 1px solid #0d6efd; text-align: center;\">Network Layer (T\u1ea7ng 3)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Vai tr\u00f2 ch\u00ednh<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Chuy\u1ec3n d\u1eef li\u1ec7u gi\u1eefa c\u00e1c thi\u1ebft b\u1ecb trong c\u00f9ng m\u1ed9t m\u1ea1ng c\u1ee5c b\u1ed9 (LAN).<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u1ecbnh tuy\u1ebfn d\u1eef li\u1ec7u gi\u1eefa c\u00e1c m\u1ea1ng kh\u00e1c nhau (WAN).<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u01a1n v\u1ecb d\u1eef li\u1ec7u<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Khung (Frame)<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">G\u00f3i (Packet)<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Lo\u1ea1i \u0111\u1ecba ch\u1ec9<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u1ecba ch\u1ec9 v\u1eadt l\u00fd (MAC Address)<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u1ecba ch\u1ec9 logic (IP Address)<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u1ecbnh d\u1ea1ng \u0111\u1ecba ch\u1ec9<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u1ecba ch\u1ec9 MAC g\u1ed3m 48 bit, \u0111\u01b0\u1ee3c g\u00e1n c\u1ee9ng tr\u00ean m\u1ed7i card m\u1ea1ng.<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u1ecba ch\u1ec9 IP g\u1ed3m 32 bit (<a href=\"https:\/\/interdata.vn\/blog\/ipv4-la-gi\/\">IPv4<\/a>) ho\u1eb7c 128 bit (<a href=\"https:\/\/interdata.vn\/blog\/ipv6-la-gi\/\">IPv6<\/a>), c\u00f3 th\u1ec3 g\u00e1n \u0111\u1ed9ng ho\u1eb7c t\u0129nh.<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Thi\u1ebft b\u1ecb m\u1ea1ng<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Switch, Bridge<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Router<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">V\u00ed d\u1ee5 giao th\u1ee9c<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Ethernet, Wi-Fi, PPP<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">IP (Internet Protocol), ICMP<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Ph\u1ea1m vi ho\u1ea1t \u0111\u1ed9ng<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">M\u1ea1ng c\u1ee5c b\u1ed9 (Local Area Network &#8211; LAN)<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">M\u1ea1ng di\u1ec7n r\u1ed9ng (Wide Area Network &#8211; WAN), Internet<\/span><\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Ch\u1ee9c n\u0103ng<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">Ph\u00e2n khung (framing), ki\u1ec3m so\u00e1t l\u1ed7i, ki\u1ec3m so\u00e1t lu\u1ed3ng, \u0111i\u1ec1u khi\u1ec3n truy c\u1eadp m\u00f4i tr\u01b0\u1eddng (MAC).<\/span><\/td>\n<td style=\"padding: 10px; border: 1px solid #0D6EFD; vertical-align: top; white-space: normal; word-break: break-word;\"><span style=\"color: #000000;\">\u0110\u1ecbnh tuy\u1ebfn (routing), x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1eddng \u0111i t\u1ed1t nh\u1ea5t cho d\u1eef li\u1ec7u.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2><span class=\"ez-toc-section\" id=\"Vi-du-thuc-te-ve-Data-Link-Layer\"><\/span><strong>V\u00ed d\u1ee5 th\u1ef1c t\u1ebf v\u1ec1 Data Link Layer<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 <strong>Data Link Layer<\/strong>, h\u00e3y xem x\u00e9t m\u1ed9t v\u00ed d\u1ee5 th\u1ef1c t\u1ebf. Gi\u1ea3 s\u1eed b\u1ea1n mu\u1ed1n g\u1eedi m\u1ed9t file t\u1eeb m\u00e1y t\u00ednh A \u0111\u1ebfn m\u00e1y t\u00ednh B trong c\u00f9ng m\u1ed9t m\u1ea1ng LAN.<\/p>\n<ul>\n<li>D\u1eef li\u1ec7u \u0111\u01b0\u1ee3c t\u1ea1o ra t\u1eeb <a href=\"https:\/\/interdata.vn\/blog\/application-layer-la-gi\/\">T\u1ea7ng \u1ee9ng d\u1ee5ng<\/a> tr\u00ean m\u00e1y A v\u00e0 \u0111i xu\u1ed1ng c\u00e1c t\u1ea7ng d\u01b0\u1edbi.<\/li>\n<li>Khi d\u1eef li\u1ec7u \u0111\u1ebfn T\u1ea7ng m\u1ea1ng (T\u1ea7ng 3), n\u00f3 \u0111\u01b0\u1ee3c \u0111\u00f3ng g\u00f3i th\u00e0nh m\u1ed9t g\u00f3i (packet) v\u1edbi \u0111\u1ecba ch\u1ec9 IP \u0111\u00edch c\u1ee7a m\u00e1y B.<\/li>\n<li>G\u00f3i n\u00e0y \u0111\u01b0\u1ee3c chuy\u1ec3n xu\u1ed1ng <strong>Data Link Layer<\/strong> (T\u1ea7ng 2). T\u1ea7ng 2 tr\u00ean m\u00e1y A s\u1ebd t\u00ecm \u0111\u1ecba ch\u1ec9 MAC c\u1ee7a m\u00e1y B trong m\u1ea1ng LAN (s\u1eed d\u1ee5ng giao th\u1ee9c ARP n\u1ebfu c\u1ea7n).<\/li>\n<li>Khi c\u00f3 \u0111\u1ecba ch\u1ec9 MAC \u0111\u00edch, <strong>Data Link Layer<\/strong> s\u1ebd t\u1ea1o m\u1ed9t khung d\u1eef li\u1ec7u (frame) m\u1edbi, th\u00eam \u0111\u1ecba ch\u1ec9 MAC ngu\u1ed3n c\u1ee7a m\u00e1y A v\u00e0 \u0111\u1ecba ch\u1ec9 MAC \u0111\u00edch c\u1ee7a m\u00e1y B v\u00e0o ti\u00eau \u0111\u1ec1, v\u00e0 th\u00eam c\u1ea3 \u0111\u1ecba ch\u1ec9 IP c\u1ee7a T\u1ea7ng 3.<\/li>\n<li>Khung d\u1eef li\u1ec7u n\u00e0y \u0111\u01b0\u1ee3c chuy\u1ec3n xu\u1ed1ng T\u1ea7ng v\u1eadt l\u00fd v\u00e0 \u0111\u01b0\u1ee3c truy\u1ec1n qua c\u00e1p m\u1ea1ng.<\/li>\n<li>Switch m\u1ea1ng nh\u1eadn khung d\u1eef li\u1ec7u n\u00e0y. D\u1ef1a v\u00e0o \u0111\u1ecba ch\u1ec9 MAC \u0111\u00edch, switch s\u1ebd chuy\u1ec3n khung d\u1eef li\u1ec7u \u0111\u00f3 \u0111\u1ebfn \u0111\u00fang c\u1ed5ng k\u1ebft n\u1ed1i v\u1edbi m\u00e1y B.<\/li>\n<li>M\u00e1y B nh\u1eadn \u0111\u01b0\u1ee3c khung d\u1eef li\u1ec7u, ki\u1ec3m tra t\u00ednh to\u00e0n v\u1eb9n v\u00e0 chuy\u1ec3n l\u00ean T\u1ea7ng m\u1ea1ng \u0111\u1ec3 x\u1eed l\u00fd.<\/li>\n<\/ul>\n<p>To\u00e0n b\u1ed9 qu\u00e1 tr\u00ecnh n\u00e0y di\u1ec5n ra ch\u1ec9 trong t\u00edch t\u1eafc, gi\u00fap vi\u1ec7c truy\u1ec1n t\u1ea3i d\u1eef li\u1ec7u tr\u1edf n\u00ean li\u1ec1n m\u1ea1ch.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Vai-tro-cua-Data-Link-Layer-trong-truyen-thong-mang\"><\/span><strong>Vai tr\u00f2 c\u1ee7a Data Link Layer trong truy\u1ec1n th\u00f4ng m\u1ea1ng<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Data Link Layer<\/strong> c\u00f3 vai tr\u00f2 c\u1ef1c k\u1ef3 quan tr\u1ecdng, l\u00e0 c\u1ea7u n\u1ed1i gi\u1eefa ph\u1ea7n m\u1ec1m (c\u00e1c t\u1ea7ng tr\u00ean) v\u00e0 ph\u1ea7n c\u1ee9ng (T\u1ea7ng v\u1eadt l\u00fd).<\/p>\n<ul>\n<li><strong>\u0110\u1ea3m b\u1ea3o truy\u1ec1n d\u1eef li\u1ec7u tin c\u1eady:<\/strong> T\u1ea7ng n\u00e0y \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00e1c bit d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n m\u1ed9t c\u00e1ch ch\u00ednh x\u00e1c t\u1eeb m\u1ed9t \u0111i\u1ec3m \u0111\u1ebfn \u0111i\u1ec3m kh\u00e1c.<\/li>\n<li><strong>Qu\u1ea3n l\u00fd truy c\u1eadp k\u00eanh truy\u1ec1n:<\/strong> Ch\u1ee9c n\u0103ng MAC c\u1ee7a <strong>Data Link Layer<\/strong> gi\u00fap nhi\u1ec1u thi\u1ebft b\u1ecb c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng chung m\u1ed9t m\u00f4i tr\u01b0\u1eddng truy\u1ec1n t\u1ea3i m\u00e0 kh\u00f4ng g\u00e2y ra xung \u0111\u1ed9t, \u0111\u1ea3m b\u1ea3o m\u1ea1ng ho\u1ea1t \u0111\u1ed9ng \u1ed5n \u0111\u1ecbnh.<\/li>\n<li><strong>\u0110\u00f3ng vai tr\u00f2 n\u1ec1n t\u1ea3ng:<\/strong> T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u cung c\u1ea5p m\u1ed9t d\u1ecbch v\u1ee5 \u0111\u00e1ng tin c\u1eady cho T\u1ea7ng m\u1ea1ng, cho ph\u00e9p T\u1ea7ng m\u1ea1ng t\u1eadp trung v\u00e0o ch\u1ee9c n\u0103ng \u0111\u1ecbnh tuy\u1ebfn g\u00f3i tin gi\u1eefa c\u00e1c m\u1ea1ng kh\u00e1c nhau m\u00e0 kh\u00f4ng c\u1ea7n b\u1eadn t\u00e2m v\u1ec1 c\u00e1c v\u1ea5n \u0111\u1ec1 v\u1eadt l\u00fd hay l\u1ed7i truy\u1ec1n t\u1ea3i.<\/li>\n<\/ul>\n<p>Hi\u1ec3u r\u00f5 <strong>Data Link Layer l\u00e0 g\u00ec<\/strong> kh\u00f4ng ch\u1ec9 gi\u00fap b\u1ea1n n\u1eafm v\u1eefng ki\u1ebfn th\u1ee9c n\u1ec1n t\u1ea3ng v\u1ec1 m\u1ea1ng m\u00e1y t\u00ednh m\u00e0 c\u00f2n l\u00e0 ch\u00eca kh\u00f3a \u0111\u1ec3 gi\u1ea3i quy\u1ebft nhi\u1ec1u s\u1ef1 c\u1ed1 m\u1ea1ng th\u1ef1c t\u1ebf. T\u1eeb vi\u1ec7c x\u00e1c \u0111\u1ecbnh l\u1ed7i k\u1ebft n\u1ed1i, hi\u1ec3u c\u00e1ch switch ho\u1ea1t \u0111\u1ed9ng, cho \u0111\u1ebfn vi\u1ec7c b\u1ea3o m\u1eadt m\u1ea1ng n\u1ed9i b\u1ed9, T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u \u0111\u00f3ng m\u1ed9t vai tr\u00f2 kh\u00f4ng th\u1ec3 thi\u1ebfu.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Trong m\u1ea1ng m\u00e1y t\u00ednh, m\u00f4 h\u00ecnh OSI (Open Systems Interconnection) l\u00e0 n\u1ec1n t\u1ea3ng quan tr\u1ecdng gi\u00fap ta hi\u1ec3u r\u00f5 c\u00e1ch d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c truy\u1ec1n t\u1eeb thi\u1ebft b\u1ecb n\u00e0y sang thi\u1ebft b\u1ecb kh\u00e1c. Trong s\u1ed1 7 t\u1ea7ng c\u1ee7a m\u00f4 h\u00ecnh OSI, Data Link Layer (T\u1ea7ng li\u00ean k\u1ebft d\u1eef li\u1ec7u) gi\u1eef vai tr\u00f2 \u0111\u1eb7c bi\u1ec7t. V\u1eady Data<\/p>\n","protected":false},"author":11,"featured_media":33008,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[151],"tags":[],"class_list":["post-33000","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mang"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/33000","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=33000"}],"version-history":[{"count":9,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/33000\/revisions"}],"predecessor-version":[{"id":36061,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/33000\/revisions\/36061"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/33008"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=33000"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=33000"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=33000"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}